1. Field of the Invention
The present invention relates to a network communication device and a network communication method, especially to a network communication device and a network communication method capable of power saving.
2. Description of Related Art
In the prior art, after a network connection is established, a traditional network device (e.g. an Ethernet network device in compliance with 1000BASE-T standard) has to send an idle pattern to a reception end continually to thereby keep the connection alive even if the network device is in an idle state with no need to do transmission or reception. Unfortunately, although the idle state is applied, the power consumption of the traditional network device is merely a bit less than that in a normal state. Therefore, in order to save more power, IEEE works out Energy Efficient Ethernet (EEE) standard which allows a network device to enter a low power idle (LPI) mode from the aforementioned idle sate to turn off the operation of a physical layer circuit in the network device under the LPI mode. In the meantime, EEE standard also requires that the network device must come back from the LPI mode to the normal state immediately to process data once a transmission or reception request occurs.
Generally speaking, an Ethernet network device conforming to 1000 BASE-T standard utilizes four pairs of wires to carry out full-duplex transmission. However, a (U.S. Pat. No. 7,835,389B2) provides a framework in compliance with 100 BASE-T standard for performing transmission by only one pair or two pairs of wires. This framework has a data transmission rate higher than that of a traditional device conforming to 1000 BASE-X standard, but it also brings much circuit complication and power consumption issues; moreover, this framework can not support EEE standard, which means that it can not enter the LPI mode to cut the operation of the physical layer circuit for power saving.